Rolling mill



y 1936- 1.. lvElsEfl 2,039,959

ROLLING MILL Filed Dec. 28, 1933 2 Sheets-Sheet l lNVENTOR May 5, 1936. L. IVERSEN 2,039,959

ROLLING MILL Filed Dec. 28, 1933 2 SheetsSheet 2 I Z ALIZIZENTOR Patented May 5, 1936 s PATENT OFFICE UNITED STATE ROLLING mu.

Lorenz Iversen, Pittsburgh, Pa., assignor to Mesta Machine Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 28, 1933, Serial No. 704,344

This invention relates to rolling mills and particularly to rolling mills of the backed-up type. Mills of this character, particularly for the roll-, ing of strip, have gone into extended use during the past few years and such use has emphasized the presence of certain limitations therein which are overcome by my invention.

In the backed-up type of mill the working rolls employed for reducing the steel or other metal to be rolled are made of a. diameter suitable for the work at hand without regard to their beam strength, the separating forces which arise during rolling being resisted by much larger and stiffer backing-up rolls. In order to supply power to the mill it has heretofore been the practice to drive the work rolls by means of a motor drive with the usual mill spindle, connection, or to drive the mill largely or entirely by tension on the delivered strip. In the former case there are definite limitations on the size of the work roll which may be employed because the neck of the roll must be sufliciently large to transmit the power, and the roll body must also have sufiicient torsional strength to transmit the power from end to end. (Various considerations, e. g., the wide spacing of the backing roll axes and hencethe necessity for a driving unit of mammoth size, make it undesirable to drive the backing rolls.) Because of the necessity of having a work roll sufiiciently strong in torsion it cannot be reduced in diameter to the extent which is frequently, desirable. In the second case above mentioned, namely, where the rolls are undriven and the power is applied through tension on the strip, there are limitations on the drafts which can be employed because if too heavy a draft is at-- tempted the metal may tear apart. In the case of a mill driven through tension on the strip, the work roll may be made very small in diameter but it must, of course, be borne in mind that the tension on the strip tends to exert a considerable force causing deflection of the work roll in the direction of travel of the strip. It has been proposed to overcome this by using buttresses or the like, but these interfere with free access to the roll pass and are undesirable for a variety of reasons, such as the necessity for changing the buttress to accommodate it to every minor change in work roll diameter occasioned by dressing of the work roll and the necessity of adjusting the buttress vertically when the screwdowns are operated.

I overcome these several dimculties and obtain the advantage of relatively small work rolls and at the same time provide for supplying all or a considerable part 01' the power required through driving the mill by torque applied to the rolls. I obtain these advantages by interposing between the small work rolls and the relatively large backing rolls intermediate rolls which are smaller than 5 the backing rolls and preferably larger than the working rolls. I arrange for driving these intermediate rolls. I also make provision for removingthe small work rolls so that the intermediate rolls may be used in direct engagement with the 1 metal.

In the accompanying drawings illustrating 'a present preferred embodiment oi the invention,

Figure 1 is a front elevation of a mill embodying the invention; i 15 Figure 2 is a vertical section partly broken away on the line 11-11 of Figure 1;

Figure 3 is a view similar to Figure 1 but show-. ing the small work rolls removed, and

Figure 4 is a section on the line IV-IV of 20 Figure 3.

The mill illustrated in the drawings comprises housings 2 having windows 3 therein for sup-' porting and guiding blocks 4 in which the several rolls are journaled. The blocks for the bot- 25 tom rolls lie at the bottoms of the windows and the blocks for the upperrolls are slidably sup-- ported in the windows, their vertical position being determined by screwdowns 5 operated by conventional mechanism 5. It is also customary to 30' I employ spring balance means for the upper rolls and these will be provided for the several upper rolls in my mill, but since such spring balance means are well known, they are omitted from the drawings in the interest of clarity.

The mill is provided with an upper backing roll I and a lower backing roll 8. These rolls are of large diameter and are'carried by suitable bearings in the blocks 4; for example, roller bearings or high pressure oil bearings. The backing 40 rolls in a mill of this character may be 4 feet or more in diameter and it will be appreciated that any attempt at driving the backing rolls. would require that all of theparts be of such great size .as to consume an undue amount of space and 45 greatly increase the cost of the mill. For this reason the backing rolls 1 and 8 are undriven.

Each of the blocks 4 has a chuck 9 slidably mounted therein and intermediate rolls I 0 and.

l i are journaled in these chucks. The rolls I0 and H are of smaller diameter than the backing rolls but .are larger than the work rolls hereinafter described. The intermediate rolls l0 and.

II make connection through the usual spindles I: with a pinion set l3 driven from a suitable power source such as reducing gearing indicated at It and connected to a driving motor not shown.

The chucks 9 are recessed to accommodate the arms l5 of chucks It in which work rolls I1 are mounted. The work rolls II are of small diameter, the dimensions depending on the particular mill and the rolling to be accomplished. It will be noted that they are smaller than the intermediate rolls Ill and l I, and, as illustrated, are of such diameter that they do not have sufiicient torsional strength to transmit the power required for rolling. If desired, the work rolls may be of different diameters, as is desirable in the rolling of certain classes of material. This may be very easily done with my improved mill, because it does not require any change in the driving mechanism. The intermediate mils which are of the same diameter will drive the work rolls at the same peripheral speed regardless of reasonable differences in work roll diameter. Preferably the intermediate rolls will be smaller than the backing rolls but longer than either of the working rolls.

The windows 3 of the housings are made sumciently high to permit of separating the backing rolls an amount sufficient to remove the work rolls I! and their supporting chucks. It will be noted from Figure 4 that when this is done the intermediate rolls l0 and II may be brought into direct contact with one another. It will also be noted that the upper of such rolls projects below and the lower of such rolls projects above its chuck and the block wherein the chuck is mounted. This permits of bringing the rolls together without interference, and also allows of redressing the rolls to a considerable extent.

When the small work rolls are removed, the mill functions as an'ordinary 4-high mill which is entirely suitable for certain classes of work.

By comparing Figures 2 and 4 it will be noted that if the direction of rolling remains the same the direction of the rotation of the intermediate rolls in and II must be reversed when the mill is changed from the fi-high setup to the 4'-high setup. This requires that a reversing drive be employed if this feature of the invention is to be utilized.

My invention makes is possible to apply a satisfactory drive to the rolls of a backed-up mill wherein the work rolls are of quite small diameter, for example, 2 or 3 inches. It will be understood, too, that in certain cases the use of the/ invention will be advantageous even though larger work rolls be employed.

I have illustrated and described a present preferred embodiment of the invention, but it will be understood that this is by way of illustration only and that it may be otherwise embodied or practiced within the scope oi. the following claims.

I claim:

1. A rolling mill comprising housings having windows, bearing means in the housings, a pair of working rolls, a pair of backing rolls of larger diameter, the backing rolls being supported by said bearing means, a roll intermediate each working roll and itsbacklng roll, and means for adjusting the bearing means toward or away from one another, the working rolls being removable from the mill and the adjusting means being so constructed and arranged as to permit of bringing the intermediate rolls into engagement with one another. a

2. A rolling mill comprising a pair of working rolls, a pair of backing rolls of larger diameter, a roll intermediate each working roll and its backing roll, and means for driving the intermediaterolls, the working rolls being removable and the backing rolls being adjustable to permit of then bringing the intermediate rolls into engagement with,one another for the rolling of material therebetwecn.

3. A rolling mill comprising a pair of working rolls, a pair of backing rolls of larger diameter, a roll intermediate each working roll and its backing roll, and means for driving the intermediate rolls, the working rolls being removable and' the backing rolls being adjustable to permit of then bringing the intermediate rolls into engagement with one another for the rolling of material therebetween, the driving means being reversible.

4. A rolling mill comprising a housing having a window therein, bearing chucks mounted in the window and relatively adjustable therein, backing rolls of large diameter mounted in the chucks, a pair of rolls of smaller diameter lying between the backing rolls, means for driving the smaller rolls, and a pair of work rolls lying between the driven rolls, the work rolls being removable and the chucks being adjustable to permit of bringing the driven rolls into substantial engagement with one another for the rolling of material therebetween, the lower driven roll having a working surface extending above the upper surface of the lower chuck and the upper driven roll having a working surface extending below the lower surface of the upper chuck.

5. A rolling mill comprising housings having windows therein, bearing chucks mounted in the windows and relatively adjustable therein, backing rolls of large diameter mounted in the chucks, a pair of work rolls of small diameter lying between the backing rolls and a pair of rolls of intermediate diameter lying one between each backing roll and its corresponding work roll, the work rolls being removable and the chucks being adjustable to permit of bringing the inter mediate rolls into substantial engagement with one another for the rolling of material therebetwecn.

, the intermediate rolls being carried by the chucks,

the working surfaces of the rolls extending beyond the adjacent faces of the upper and lower chucks.

6. A rolling mill comprising housings having windows therein, bearing blocks mounted in the windows and relatively adjustable in such windows, backing rolls of large diameter journalcd in the blocks, a pair of work rolls of small diameter lying between the backing rolls and adapted to engage opposite sides of a work piece passing through the mill, a pair of rolls of intermediate diameter lying one between each backing roll and its corresponding work roll, chucks for the inter- -mediate rolls, the chucks being slidably mounted in the bearingblocks, the work rolls being removable and the blocks being adjustable to permit of windows and relatively adjustable therein, backing rolls of large diameter mounted in the blocks, the backing rolls being undriven, a pair of work rolls of small diameter lying between the backing rolls, the work rolls being undriven, and a pair of rolls of intermediate diameter lying one between each backing roll and its corresponding work roll, the work rolls being removable and the blocks being adjustable to permit of bringing the intermediate rolls into such relation one with the other that they may engage the opposite surfaces of a work piece passing therebetween, and means for driving the intermediate rolls.

8. A rolling mill comprising housings having windows therein, bearing blocks mounted in the windows and relatively adjustable therein, backing rolls of large diameter mounted in the blocks. the backing rolls being undriven, a pair of work rolls of small diameter lying between the backing rolls, the work rolls being undriven, a pair of rolls of intermediate diameter lying one between each backing roll and its corresponding work roll, the work rolls being removable and the blocks being adjustable to permit of bringing the intermediate rolls into such relationone with the other that they may engage the opposite surfaces of a work piece passing therebetween, and means for driving the intermediate rolls, the driving means being reversible.

LORENZ IVERSEN. 

